Carbureter.



H. E. cums.

CABBURETER. v

I I APPLICATION HLED MAY 27, 1916. mama? 1. Patented July 17, 1917-.

lbw

H ATT FH" 1 ra n sratras Parana onion.

HENRY E. CURTIS, OF SAN J OSE, CALIFyORNIA, ASSIGNOR CF DEE-THIRD TO FRANK P.

SCHEMMEIL, OF SAN JOSE, CALIFORNIA.

CAEBURETER.

Application filed May 27, 1916. Serial No. 106,363.

' citizen or the United States, and residentof San Jose, in the county of Santa Clara and State of California, have invented certain new and useful Improvements in Car;

bureters, of which the following is a specification.

My 1nvent1on relates to carburetors, and

particularly to the means for regulating the fuel and air mixture in the same.

One object of my invention is to provide means for automatically regulating the in: flow or' air, into the carburetor so that the quantity of air drawn in will at all times be in proper proportion to the amount of fuel being used, and to provide a means of the nature specified that will be simple, compact, efiicient and cheap to manufacture. Other objects of my invention are, to provide a carburetor provided with a Venturi tube that is self cleaning, that is revolubly as well as slidably mounted, and that is provided with means for causing it to revolve automatically when in use.

With the above and other objects in view,

relative arrangement of parts as hereinafter described, and illustrated in the accompan 111 drawings, 1n wh1ch,-

higurel shows a sectional view of a carbureter embodying my invention.

Fig. 2 shows a sectional view on line A-Aof Fig. 1.

Fig. 3 shows a sectional" view of a Venturi tube fitted with vanes.

Fig. l shows a bottom view of the tube shown in Fig. 3.

Fig. 5 shows. a sectional view on line .'BB of Fig. 1.

Similar characters of reference refer to similar parts throughout the several views.

Referring nowmore particularly to the drawings, 1 indicates the float chamber of a carburetor, 2 the inner wall of said chamber, 3 the tloat and 4 the liquid fuel in said chamber.

shape and is a continuation of primary air chamber 7, said air chamber 7 being formed of the inner wall 2 of float chamber 3. A shouldcrB is formed in the inner surface of wall 2 as shown andfor the purposeiherein- Specification of Letters Patent.

and revolubly positioned in ,primaryaii' At 5 is indicated the mixing chamber provided with a throttle valve 6. Mixing chamber 5 is shown cylindrical in llatcnted July raisin.

after set forth. At 9 is shown a spraying tube concentrically and axially positioned in said primary air chamber 7, the samebe-i'. ing held in. position by webs 10 preferably cast as an. integral part of inner wall-2. Chamber 11 with its outer cndiclosed by plug 12 and comiected to float chamber l' by conduits 13, provides a means by which fuel 1i may be drawn from float chamber 1 through spraying tube 9 to the carburetingjchamber 17". At 14 are shown air inlet-ports formed in the wall of the carburetor abovefifloat chamber 1.

At 15 I showa true Venturi tube sl-idably.

chamber 7 in the following manner and having the following characteristics:g'lhe lowermost portion of the tube has an inner; 5; surface 16 in the form of a short truncated; cone joined to the lower and smaller endof '15 a comparatively longer truncated cone 17 by a short throat-piece 18, cone 17 formingthe carbureting chamber 17% The outer-z surface of the lower portion of said Your. turi tube 15, shown at 15, is of such a form and size as to slide easily in the lower pore tion of rimary chamber 7, and isprovided wlth a flange 20 of the, proper size and form to engage shoulder 8 in wall 2. The outer surface of the upper portion of tube 15. indicated at 15, is of the proper size and form to slide easily in chamber? and has, preferably, three annular grooves, formed therein as indicated at 26, 27 and 28 respectively. At 29 are shown a numberfoit' small perforations or conduits connecting groove 27 with chamber 5. Groove'28 isl f formed to diminish the weight nassis} and to collect the material, as it adi ances and retracts, that might otherwise gather on the inner surfaces of the webs between ii ports 14. Grooves 26 and 27, one on each I side of groove 28, are provided to act as re ceptacles for any particles that might pone trate the space between tube l5'and' wall 2 and thereby interfere with the free longitudinal or revolving movement oi said tube; Conduits 29 permit a small amount of air to enter chamber 5 when tube 15 is slightly ad-T vanced upon starting the engine thereby preventing too rich a mixture and a quick, even start is effected, the continued action V of, the engine causing tube 15 to still further advance and thereby bringing apertures 23 into use and thus adjusting the. inflow- .of 1 10 in any plane or 7 under proper control.

condensed vapor that might the engine is .which interferes with struction that might air and fuel to the changing requirements of the engine when in operation. The relation of flange 20 to shoulder'8 is such that when started tube 15 does not-at once jump forward to the limit of its forward movement, but advances a little way' quickly when it is retarded by the slow entrance of air into the space between flange 20 and shoulder 8, thespeed of its continued forward movement depending of course upon the pull of the engine. Inasmuch as tube 15 is of light weight it is extremely sensil tive to the varying pressures in chambers 17 and 5 due to the varying speed and load of the engine, and consequently is susceptible of accurate adjustment and control. Apertures or orifices 23 are angularly positioned with relation to any plane or planes passing transversely through tube 15 at right angles to its axis and are so positioned in tube 15 as to permit the passage of air through openings 14 and passage 21 to mixing chamber 5 when tube 15 is advanced a distance. Passage 21 is formed by cutting away a large proportion ofthe exterior of the wall of cone 1? thereby reducing the weight of tube 15. l

I have found that if orifices 23 are placed planes passing transversely through tube 15 at right angles to its axis, the air drawn therethrough tends to form a blanket in chamber 17, or over the same,

the proper and uniform feeding of fuel and air from nozzle of spraying tube 9 and throat: 18, but by placing orifices 23 in the angular position described this-trouble is entirely eliminated and the flow of air and fuel is uniform and Orifices 23 are not .only a-ngularly positioned with reference to any plane or planes passing through tube 15 at right angles to its axis, but are also angularly positioned with relation to any plane or planes passing through the axis of said tube andin which the said axis lies as clearly shown in Fig. 5. The functions performed by orifices 23 are fivefold. First, they assist in advancing tube 15 through the suction of air therethrough; second, they practically eliminate condensation troubles by provid ing inwardly and upwardly flowing jets of air in that portion of the tube 15 in which an eddy of vapor is most likely to be formed and consequently Where condensation is most likely to take place; third, they pro-. vide jets of air in close proximity to each other in such a manneras to pick up any from the mixing chamber 5,

and vaporize the same; fourth,

being angular-1y positioned with relation to any plane in which the axis of said tube lies, the movement of air therethrough causes said tube torevolve thereby keeping it at all times free from any ob-' otherwise form positioned orifices work down about 4 revolving of the tube through the medium of orifices. 234s effected by the reaction of the air against the sides of said angularly on its passage therethrough, the numerous angular surfaces thus presentedto the air being, in fact, equivalent to that number of vanes in a fan. This revolving movement may also be secured by forming or positioning vanes or -fins in the owericone' portion 16 as shown at 16, or the same may be used in the ori ces 23 hereinbefore described. An important function performed by the revolvin of tube'15 in the manner above set forth is that the air enteringchamber 17 is caused to whirl more or less rapidly therein and therefore a more perfect vaporization of'the fuel is obtained. This revolving motion of tube 15 also assists in throwing condensed fuel out of chamber 17 through the action of centrifugal force,

When this carbureter is in position and in full operation its action is as follows Assuming that the engine is' running under a light load, a comparatively small amount of fuel is being used and the proper amount of air is being drawn in through air chamber 7, and through throat-piece 18 because tube 15 is in a retracted position and the discharge end 24of spraying tube 9 is thereby advanced into cone 17.

If now the engine load is increased and the throttle valve6 opened wide and an increased amount of air and liquid fuel is drawninto the device the following result is effected. The increased velocity of the air drawn infrom .chamber 7 through throat-piece 18 and the suction ofair through orifices 23, causes Venturi tube 15 to advance to a position, say, as indicated in dotted lines at 25, the discharge end 24; of spraying .from the discharge end of spraying tube 9,

the increased velocity of air piece 18 being due of course to the con tracted space relative to the cones 16 and 17. The tube-15 is, of course, revolving continuously as hereinbefore described, and at a. variable speed according to the velocity of the air drawn in. v

It may now be seen that the action of my improvedzcarbureter is entirely automatic, as the pbsition of tube 15 depends entirely upon the fluid pressure within the same. When the engine load is heavy and the fluid pressure light the tube 15 is advanced as shown, a large amount of air is drawn into mixing chamber 5 and a proportionally large in said throatconjunction with meats? amount of liquid fuel is drawn from float chamber 1. As the engine load lightens the diminished suction of air permits tube to recede thus diminishing the suction of J liquid fuel from spraying tube 9.

- parative slowness with which air can be did drawn into the space between flange 20 and shoulder 8, Likewise the comparative slow discharge of air from the space between flange 20 and shoulder 8 steadies and regulates the motion of tube 15 upon its return movement when the engine pull is decreased. This dash-pot is desirable as it provides for the gradual movement of tube 15 in either direction according to the necessities of the engine, and thus provides for the exact proportioning of the liquid fuel and air mixture during any and all positions or the throttle valve and ell'ectually prevents chattering or fluttering of the tube. in order to secure this dash-pot action the lower portion of tube 15 is lengthened suliiciently to provide a comparatively long surface 15 thereby retarding the passage of airfrom the space between flange 20 and shoulder 8 to the lower portion of chamber 7, and the outer surface of flange 20 is made of the proper width to retard the passage of air from the space between flange 20 and shoulder 8 to passage (in account o-i' this construction, when the engine load changes and the tube falls or advances, the air between flange 29 and shoulder 8 can escape but slowly thereby providing the dash-pot action desired. Grooves 15 are formed in surface 15 to act as receptacles for any particles that might penetrate the space between surface 15 and wall 2.

While I have herein described and shown 'one particular' form 'of construc tion of my improved carburetor, it is under stood that changes in form and construction and minor details may be made within. the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:-

1. In a carburetor having compensating air inlet ports and. 'a fuel nozzle; a fluid pressure contro lled Venturi tube slidably and revolubly mounted therein in operative relation to said nozzle and'said ports,

Y said tube being provided with means for imparting a rotary motion thereto by the passage of air therethrough.

2.111 a carburetor having compensating air inlet portsand a fuel nozzle, a fluidpressure-controlled Venturi tube slidably and rcvclublymounted. therein in operative relation to said nozzle and said ports, said tube being provided with means for low parting a rotary motion thereto by the passage of air thcrethrcugh, said means comprising: a plurality of perforations formed in said tube and angularly positioned. with relation. to any plane or planes passingr' through said tube and in which the. axis of said tube lies.

3. In a carburetor having compensating air inlet ports and. a fuel nozzle, a perforated fluid-prossure-controlled Venturi tube slidably and revolubly mounted therein in operative relation to said nozzle and said ports, said tube being provided with means for imparting a rotary motion thereto by the passage of air therethrough.

4-. In a carburetor having compensating air inlet ports and a fuel nozzle, fluidpressure-controlled Venturi tube slidably and revolubly mounted therein in operative relation to said nozzle and said ports, tube being provided with means for impart ing'a rotary motion thereto by the passage of air therethrough, said means comprising .a plurality of perforations formed in said tube and angularly positioned with. relation to any plane or planes passing through said tube and in which the axis of said tube lies and angularly positioned with relation to any plane or planes passing" through said tube at right angles to its axis.

5'. In a carbureter having: compensating air inlet ports a fuel nozzle, a fluidpressure-controlled Venturi tube slidably and revolubly mounted therein in operative relation to said nozzle and said ports, said tube being provided with means for iniparting a rotary motion {thereto by the sage of air therethrough, and for steadvine; the movements of said tube.

6. In a carburetor having compensating air inlet ports and a fuel nozzle, a fluidpressure-controllcd Venturi tube slidably and revolubly mounted therein in operative relation to said nozzle and said ports, said tube having an annular passage formed in the outer surface thereof and. a plurality of orifices formed therein connecting said passage with the interior of said tube and an gularly positioned with relation to any plane or planes passing through said tube and in. which the axis oi said tlllDBllBS, and means for steadying the movements oi. said tube.

7. In a carburetor having conipensating' tive relation to said nozzle and said ports said tube having a plurality of annular grooves and an annular passage formed in the outer surtacc thereof and a plurality of orifices formed therein connecting said passage with the interior of said tube and angularly positioned with relation to any planeor planes passing through said tube and in which the axis of said tube lies and means for steady ng the movements ofsaid 5 tube.

J relation to said nozzle and said ports, said tube having a plurality of annular grooves and an annular passage formed in the outer surface theme a plurality of orifices formed therein connecting one of said grooves with the interior of said tube, and a plurality of orifices formed therein connecting said passage with the interior '01 said tube and angularly positioned with relation to any plane or planes passing through said tube and in which the axis of said tube lies and means for steadying the movements of said tube.

In testimony whereof I have hereunto afiixed my signature this 20th day of May,

HENRY 11 CURTIS. 

